Pollution Issues in Coastal Lagoons in the Gulf of Mexico

The coastline of the Mexican Gulf of Mexico is an area of paramount importance. It poses valuable biological and ecological resources such as coastal lagoons, rivers, estuaries, wetlands and swamps. It poses 206 coastal systems including 73 coastal lagoons with high biological richness. Their study shows the physicochemical characteristics and pollution levels into the four more productive lagoons of Tampamachoco, Mandinga, Alvarado in the Veracruz state and Terminos Lagoon in Campeche state, México, have the present characteristics. The lagoons show a wide interval in physiochemical parameters (temperature: 18–32°C, salinity: 11–38 ups, and nutrients: oxygen 1.8–9.0 mg/L, total phosphorus 2.6–123 μM total nitrogen 5–70 μM, and chlorophyll 10–50 mg/m3). All of them oscillated between normal to eutrophication condition. The presence of PAHs and some of the high toxicity as anthracene, and chrysene, as well as naphthalene and its methyl derivatives has been reported. Also, chlorinated hydrocarbons used for agriculture purposes and malaria control (DDT, lindane, endosulfan) have been identified in these lagoons. Metals as Cr, Pb, Ni, Cd, and V among others were recently reported in the lagoons considered in this study. Concentrations of pollutants also show significant variations depending on the time and the type of lagoon, or estuary

Effects of exposure to nitrite on the antioxidant enzymes activity and the histopathological response of prawn Palaemonetes argentinus

The aim of the present study was to determine lethal and sublethal effects of nitrite on the freshwater prawn, Palaemonetes argentinus (Nobili 1901). The 24, 48, 72 and 96 h median lethal concentration (LC50) of nitrite were found to be 103.07; 91.94; 82.39 and 62.53 mg L-1, respectively. The antioxidant activity of superoxide dismutase (SOD) was positively correlated with the concentration of nitrite in the environment, thus increasing the formation of hydrogen peroxide, substrate of catalase (CAT), which also showed an increased activity under the same experimental conditions. Histological samples showed that nitrite exposure caused hyperplasia, necrosis and changes in the lamellar epithelium in gills; while the effects in the hepatopancreas were degenerative desquamation, epithelial deterioration and hyperplasia. In conclusion, nitrite toxicity in P. argentinus increases with time of exposure. Moreover, this study proves that histological analysis of crustacean gills and/or hepatopancreas is a useful tool to determine the presence of toxic concentrations of nitrite in the water. Additionally, the measurement of the activity of antioxidant enzymes (e.g., SOD and CAT) as possible indicators of nitrite pollution should be considered in future studies.El objetivo del presente estudio fue determinar los efectos letales y subletales del nitrito en el camarón de agua dulce, Palaemonetes argentinus (Nobili 1901). Las concentraciones letales medias (LC50) de nitrito a las 24; 48; 72 y 96 h al nitrito fueron 103,07; 91,94; 82,39 y 62,53 mg L-1, respectivamente. La actividad antioxidante de la superóxido dismutasa (SOD) se correlacionó positivamente con la concentración de nitrito ambiental; este incremento en su actividad eleva la formación de peróxido de hidrógeno, sustrato de la catalasa (CAT), que también mostró un incremento en su actividad bajo las mismas condiciones experimentales. Las muestras histológicas evidenciaron que la exposición al nitrito causa hiperplasia, necrosis y cambios en el epitelio lamelar en las branquias; mientras que en el hepatopancreas los efectos son descamación degenerativa, deterioro epitelial e hiperplasia. En conclusión, la toxicidad del nitrito en P. argentinus se incrementa conforme el tiempo de exposición. Este estudio demuestra que el análisis histológico de las branquias y/o hepatopancreas del camarón P. argentinus es útil para determinar la presencia de concentraciones tóxicas de nitrito en el agua. Además, la medición de las enzimas antioxidantes (por ejemplo, SOD y CAT) debería ser considerado en futuros estudios como posibles indicadores de contaminación por nitrito

Xylem surfactants introduce a new element to the cohesion-tension theory

Vascular plants transport water under negative pressure without constantly creating gas bubbles that would disable their hydraulic systems. Attempts to replicate this feat in artificial systems almost invariably result in bubble formation, except under highly controlled conditions with pure water and only hydrophilic surfaces present. In theory, conditions in the xylem should favor bubble nucleation even more: there are millions of conduits with at least some hydrophobic surfaces, and xylem sap is saturated or sometimes supersaturated with atmospheric gas and may contain surface-active molecules that can lower surface tension. So how do plants transport water under negative pressure? Here, we show that angiosperm xylem contains abundant hydrophobic surfaces as well as insoluble lipid surfactants, including phospholipids, and proteins, a composition similar to pulmonary surfactants. Lipid surfactants were found in xylem sap and as nanoparticles under transmission electron microscopy in pores of intervessel pit membranes and deposited on vessel wall surfaces. Nanoparticles observed in xylem sap via nanoparticle-tracking analysis included surfactant-coated nanobubbles when examined by freeze-fracture electron microscopy. Based on their fracture behavior, this technique is able to distinguish between dense-core particles, liquid-filled, bilayer-coated vesicles/liposomes, and gas-filled bubbles. Xylem surfactants showed strong surface activity that reduces surface tension to low values when concentrated as they are in pit membrane pores. We hypothesize that xylem surfactants support water transport under negative pressure as explained by the cohesion-tension theory by coating hydrophobic surfaces and nanobubbles, thereby keeping the latter below the critical size at which bubbles would expand to form embolisms

Effects of exposure to nitrite on the antioxidant enzymes activity and the histopathological response of prawn Palaemonetes argentinus

The aim of the present study was to determine lethal and sublethal effects of nitrite on the freshwater prawn, Palaemonetes argentinus (Nobili 1901). The 24, 48, 72 and 96 h median lethal concentration (LC50) of nitrite were found to be 103.07; 91.94; 82.39 and 62.53 mg L-1, respectively. The antioxidant activity of superoxide dismutase (SOD) was positively correlated with the concentration of nitrite in the environment, thus increasing the formation of hydrogen peroxide, substrate of catalase (CAT), which also showed an increased activity under the same experimental conditions. Histological samples showed that nitrite exposure caused hyperplasia, necrosis and changes in the lamellar epithelium in gills; while the effects in the hepatopancreas were degenerative desquamation, epithelial deterioration and hyperplasia. In conclusion, nitrite toxicity in P. argentinus increases with time of exposure. Moreover, this study proves that histological analysis of crustacean gills and/or hepatopancreas is a useful tool to determine the presence of toxic concentrations of nitrite in the water. Additionally, the measurement of the activity of antioxidant enzymes (e.g., SOD and CAT) as possible indicators of nitrite pollution should be considered in future studies.El objetivo del presente estudio fue determinar los efectos letales y subletales del nitrito en el camarón de agua dulce, Palaemonetes argentinus (Nobili 1901). Las concentraciones letales medias (LC50) de nitrito a las 24; 48; 72 y 96 h al nitrito fueron 103,07; 91,94; 82,39 y 62,53 mg L-1, respectivamente. La actividad antioxidante de la superóxido dismutasa (SOD) se correlacionó positivamente con la concentración de nitrito ambiental; este incremento en su actividad eleva la formación de peróxido de hidrógeno, sustrato de la catalasa (CAT), que también mostró un incremento en su actividad bajo las mismas condiciones experimentales. Las muestras histológicas evidenciaron que la exposición al nitrito causa hiperplasia, necrosis y cambios en el epitelio lamelar en las branquias; mientras que en el hepatopancreas los efectos son descamación degenerativa, deterioro epitelial e hiperplasia. En conclusión, la toxicidad del nitrito en P. argentinus se incrementa conforme el tiempo de exposición. Este estudio demuestra que el análisis histológico de las branquias y/o hepatopancreas del camarón P. argentinus es útil para determinar la presencia de concentraciones tóxicas de nitrito en el agua. Además, la medición de las enzimas antioxidantes (por ejemplo, SOD y CAT) debería ser considerado en futuros estudios como posibles indicadores de contaminación por nitrito

Patrimonio urbano y planeamiento: la protección del paisaje patrimonial a través del planeamiento especial

El presente capítulo tiene como objeto aproximarse a la metodología docente de la asignatura Patrimonio Urbano y Planeamiento, optativa que imparte el Departamento de Urbanística y Ordenación del Territorio en quinto curso del Grado en Arquitectura (Plan 2010) y del Grado en Fundamentos de Arquitectura (Plan 2012) de la Universidad de Sevilla

In vitro and in vivo efficacy of Larrea divaricata extract for the management of Phytophthora palmivora in olive trees

Phytophthora palmivora is a ubiquitous pathogen responsible for “dry branch” disease, causing significant economic losses in olive trees. Synthetic chemical fungicides are currently used for the control of P. palmivora. The general concern about the negative consequences of using synthetic products prioritizes the search for eco-friendly alternatives. In this context, plant extracts have emerged as an interesting and promising alternative for crop protection. This work studies the inhibitory activity of Larrea divaricata extract on P. palmivora mycelial growth, sporangium and zoospore production. The extract showed fungicidal activity against P. palmivora mycelial growth at concentrations over 150 mg mL-1. Specifically, the extract at 50 mg mL-1 completely suppressed the production of P. palmivora sporangia and zoospores. The alkaloid piperine in L. divaricata extract showed antimicrobial activity against P. palmivora mycelial growth. Extract effectiveness was also evaluated on olive trees in a greenhouse, showing 63% of disease reduction. These results support the use of L. divaricata extract as another environmentally friendly tool to be included in an integrated disease management program for dry branch disease caused by P. palmivora. Highlights: L. divaricata extract showed an effective antimicrobial activity against P. palmivora. Piperine was identified in the divaricata extract by HPLC/MWD. The alkaloid piperine in divaricata extract showed antimicrobial activity on the mycelial growth of P. palmivora. L. divaricata extract could be included in an integrated management programme for dry branch disease caused by P. palmivora.Phytophthora palmivora is a ubiquitous pathogen responsible for “dry branch” disease, causing significant economic losses in olive trees. Synthetic chemical fungicides are currently used for the control of P. palmivora. The general concern about the negative consequences of using synthetic products prioritizes the search for eco-friendly alternatives. In this context, plant extracts have emerged as an interesting and promising alternative for crop protection. This work studies the inhibitory activity of Larrea divaricata extract on P. palmivora mycelial growth, sporangium and zoospore production. The extract showed fungicidal activity against P. palmivora mycelial growth at concentrations over 150 mg mL-1. Specifically, the extract at 50 mg mL-1 completely suppressed the production of P. palmivora sporangia and zoospores. The alkaloid piperine in L. divaricata extract showed antimicrobial activity against P. palmivora mycelial growth. Extract effectiveness was also evaluated on olive trees in a greenhouse, showing 63% of disease reduction. These results support the use of L. divaricata extract as another environmentally friendly tool to be included in an integrated disease management program for dry branch disease caused by P. palmivora. Highlights: L. divaricata extract showed an effective antimicrobial activity against P. palmivora. Piperine was identified in the divaricata extract by HPLC/MWD. The alkaloid piperine in divaricata extract showed antimicrobial activity on the mycelial growth of P. palmivora. L. divaricata extract could be included in an integrated management programme for dry branch disease caused by P. palmivora

Efectos de cantaxantina dietaria sobre el estres por radiacion ultravioleta en el camarón Artemesia longinaris

The aims of this research were to investigate the effects of diets with added synthetic canthaxanthin (10% parafarm) and to evaluate its possible protective role under ultraviolet radiation (UVR) in prawn Artemesia longinaris. Three isoproteic and isolipidic diets (41% protein and 12% lipid) containing 0 (C0), 100 (C100), and 300 (C300) mg of canthaxanthin kg-1 of diet were prepared. Before initiating the radiation experiment, prawns were fed with the different diets for a period of 21 d in order to determine a possible accumulation of carotenoids. Afterwards, animals were exposed to two radiation treatments for 7 d: a) photosynthetically active radiation (PAR, 400-700 nm), and b) total radiation (PAR+UVR, 280-700 nm), under controlled conditions (19 ± 2 °C, salinity = 33, pH = 7). In animals exposed to PAR+UVR treatment, survival varied between 50 and 83.33% with the highest value in animals fed diet C300. At the end of the experiment, significant statistical differences were registered in integument carotenoid concentration. Under UVR stress, the highest decrease in non-polar carotenoid and esterified astaxanthin were recorded in prawns fed diets containing canthaxanthin. Scavenging properties were evaluated by electron resonance spectroscopy (EPR) using the stable 2,2-diphenyl-2-picrylhydrazyl (DPPH) radical. Prawns fed with C300 showed the greatest activity to quench DPPH. Results suggested that dietary canthaxanthin could be acting as an antioxidant against reactive oxygen species and produced high tolerance under UVR stress.Los objetivos de esta investigación fueron investigar los efectos de dietas adicionadas con cataxantina sintética (10% parafarm) y evaluar su posible papel protector bajo la radiación ultravioleta (RUV) en el camarón Artemesia longinaris. Se prepararon tres dietas isoprotéicas e isolipídicas (41% proteína y 12% lípidos) con 0 (C0), 100 (C100) y 300 (C300) mg de cantaxantina kg-1 de dieta. Previo al experimento de radiación, los camarones fueron alimentados con las diferentes dietas durante 21 d para determinar una posible acumulación de carotenoides. Posteriormente, los animales fueron expuestos a dos tratamientos de radiación durante 7 d: a) radiación fotosintéticamente activa (PAR, 400-700 nm), y b) radiación total (PAR+RUV, 280-700 nm), bajo condiciones controladas (19 ± 2 °C, salinidad = 33, pH = 7). En los individuos expuestos al tratamiento PAR+RUV, la supervivencia varió entre 50 y 83,33%, con el valor más alto en animales alimentados con dieta C300. Al final del experimento, se registraron diferencias estadísticas significativas en la concentración de carotenoides en el tegumento. Bajo estrés por RUV se registró la mayor disminución de carotenoides no polares y astaxantina esterificada en camarones alimentados con dietas con cataxantina. La capacidad antioxidante se evaluó mediante espectroscopía de resonancia electrónica (EPR) utilizando el radical estable 2,2-difenil-2-picrilhidrazilo (DPPH). Los camarones alimentados con C300 mostraron la mayor actividad evidenciada por el decaimiento de DPPH. Los resultados sugirieron que la cantaxantina dietaria podría estar actuando como un antioxidante contra las especies reactivas de oxígeno y producir una alta tolerancia bajo estrés por RUV

Differences among Sociodemographic Variables, Physical Fitness Levels, and Body Composition with Adherence to Regular Physical Activity in Older Adults from the EXERNET Multicenter Study

[EN] The aim of this study was to explore the differences among between adherence to physical activity (PA) and sociodemographic variables, body composition, and physical fitness levels in older adults (>65 years). A number of 2712 participants (2086 female; 76.92%) ranging from 65 to 92 years, participated in the study. Stages of change (SoC) for PA from the transtheoretical model of change (TTM), together with different sociodemographic variables, physical fitness tests (Senior Fitness Test), and waist and hip circumferences were evaluated. Significant differences were found in age, gender, educational level, current income, physical fitness test, and body composition (all of them, p < 0.05), according to the different SoC. Greater adherence to PA practice (action and maintenance stages) was related to better academic level, higher economic income, the male gender, better results in the physical fitness test, and healthier anthropometrics perimeters. Future research is needed to identify the relationship between these variables longitudinally.SIMinisterio de Ciencia, Innovación y Universidades, Gobierno de Españ